1. Field of the Invention
The present invention relates to rotating anode x-ray tubes, and in particular to such x-ray tubes wherein the anode is magnetically seated in a housing in a non-contacting manner.
2. Description of the Prior Art
A rotating anode x-ray tube is described in German No. OS 30 43 670 wherein the shaft of the anode is magnetically seated in a housing in a non-contacting manner. The seating of the anode shaft is accomplished by a non-contacting magnetic bearing, which axially and radially holds the shaft. Because the anode is maintained suspended during operation, a problem exists in carrying away the anode current. The solution is this problem described in German No. OS 30 43 670 is to arrange at least one auxiliary cathode on a component rotating together with the anode, this auxiliary cathode having a stationary auxiliary anode allocated thereto. Dissipation of the anode current occurs through an auxiliary diode which is disposed at the anode side, so that direct contact between the auxiliary anode and auxiliary cathode does not occur. As a result of the required auxiliary cathode and auxiliary anode, however, the outlay for this structure is high.